Composite filaments and fibers

ABSTRACT

COMPOSITE FIBERS IN WHICH AT LEAST TWO POLYMERIC COMPONENTS ARE ARRANGED IN INTIMATE MUTUAL CONTACT ALONG THE FIBER LENGTH, AND AT LEAST ONE OF THE SAID COMPONENTS IS A FIBER-FORMING POLYESTER, AND THE OTHER OF THE SAID COMPONENTS IS A POLYETHER-POLYAMIDE-BLOCK-COPOLYMER COMPOSED OF LINEAR POLYAMIDE SEGMENTS AND POLYALKYLENE ETHER SEGMENTS, THE POLYALKYLENE ETHER SEGMENT CONTENT OF THE COPLYMER BEING 3 TO 85% BY WEIGHT, AND THE POLYALKYLENE ETHER SEGMENT CONTENT OF THE COMPOSITE FIVERS BEING 0.3 TO 30% BY WEIGHT.

United States Patent 3,558,419 COMPOSITE FILAMENTS AND FIBERS Kaoru Okazaki, Asaharu Nakagawa, and Kenji Sugii, Nagoya, Japan, assignors to Toyo Rayon Kabushiki Kaisha, Tokyo, Japan, a corporation of Japan No Drawing. Filed May 27, 1968, Ser. No. 732,105 Int. Cl. D02g 1/18, 3/36 U.S. Cl. 161-173 24 Claims ABSTRACT OF THE DISCLOSURE Composite fibers in which at least two polymeric This invention relates to composite filaments and fibers. More particularly, the invention relates to composite filaments and fibers of excellent antistatic property, hygroscopicity, dyeability and which furthermore possess improved hand.

Snythetic polyester filaments and fibers exhibit numbers of desirable advantages such as excellent mechanical properties and durability. Accordingly they are used with wide application areas including the field of textile fabrics. However, the commercially available polyester fibers are less satisfactory compared with natural wool, in such respects as stretchability, compression resistance, liveliness, hygroscopicity, dyeability, antistatic property and surface feeling. Many attempts have been made, accordingly, to impart one or more of the desirable properties of wool to polyester fibers, without appreciably impairing the inherent advantageous properties of the latter. However, none ever succeeded to simultaneously improve the hygroscopicity, antistatic property, stretchability and feeling of polyester fibers to the levels close to those qualities of wool. Method of achieving such, therefore, is one of the greatest pending problems of the concerned trade.

Some of the heretofore proposed attempts to improve the polyester fiber properties to bring about better qualitative resemblance to wool included the preparation of composite filaments or fibers of which at least one of the components is polyester. In majority of the attempts, same type of polymers, i.e., resembling polyesters of different shrinkages, are composed or combined for the reason of better adhesion between or among the components. Thus obtained composite fibers may be satisfactory as to crimping property, but the improvements in their hygroscopicity, antistatic property and dyeability are comparatively negligible. That is, for a composite fiber to exhibit good hygroscopicity, antistatic property and dyeability, at least one of its components must possess such characteristics. Normally, therefore, such characteristics are imparted by bonding one or more hydrophilic monomers with polyester component, by means of copolymerizaton. However, in order to achieve the improvement of the desired level, a considerably large amount of hydrophilic monomer component must be compounded with polyester component. Whereas, polyesters bonded with such large amounts of hydrophilic monomer no more retain their orginal,' excellent mechanical properties and durability. Also there was another attempt in which a minor amount of hydrophilic compound, for

3,558,419 Patented Jan. 26, 1971 example, polyethylene glycol, is mixed with a component of composite fibers in order to improve the antistatic property and hygroscopicity of the product. The result was that, although the desirable mechanical properties inherent in polyester fibers were retained, so imparted characteristics are not lasting.

On the other hand, composite fibers made from different types of polymers, for instance, polyester and polyamide, have been proposed. Because polyamide has a better dyeability and hygroscopicity than polyester, such composite fibers possess improved dyeability and hygroscopicity over polyester fibers, and concurrently exhibit the desirable properties of both polyester and polyamide fibers. Polyester and polyamide, however are poorly compatible, or have poor adhesibility to each other. Therefore the product has a fatal deficiency in that the two components tend to be separated during processing or usage. Accordmgly, normally core-in-sheath type structure is employed for this type of composite fibers, and side-by-side type structure is unsuitable.

Whereas, the following facts have now been found, i.e.:

(l) Polyalkylene ether polyamide block-copolymer which contains linear polyamide segments and polyalkylene ether segments has better compatibility with polyester than homopolyamide. Inter alia, polyalkylene etherpolyamide-block-copolymer containing 3 to 85% by weight, preferably 8 to by weight, of polyalkylene ether segments; and mixtures of polyalkylene ether-polyamide-block-copolymer with polyamide which contain 3 to weight percent, preferably 8 to 60 weight percent, of polyalkylene ether segments exhibit far better adhesibility with polyester than homopolyamide.

(2) The composite fibers obtained by composing the above block-copolymer or the mixture thereof with polyamide with a fiber-forming polyester at such a ratio that the said polyalkylene ether segments should occupy 0.3 to 30% by weight of the composite fibers, retain the desirable properties inherent in polyester fibers and concurrently possess excellent antistatic property as well as good hygroscopicity and dyeability.

(3) Furthermore, the composite fibers composed of a polyester of high modulus and the block-copolymer which is elastic and has a low modulus possess an excellent feeling, such as never expected from the fibers of any single component.

(4) Most of the composite fibers described are crimpable.

Thus, the present invention provides composite filaments or fibers in which at least two polymeric components are arranged in intimate adherence to each other along the length of the filament or fiber and one of the component is a fiber-forming polyester, characterized in that the another essential component is a polyalkylene ether-polyamide-block-copolymer or a mixture of the blockcopolymer with a fiber-forming polyamide, said copolymer comprising synthetic linear polyamide segments and 3 to 85% by weight of polyalkylene ether segments, and that the amount of the polyalkylene ether segments based on the composite filaments or fibers is 0.3 to 30% by weight.

The polyalkylene ether-polyamide-block-copolymer employed in the invention must contain 3 to 85 percent by weight of polyalkylene ether segments. Such copolymers containing less than 3 weight percent, or more than 85 weight percent, of the ether segments exhibit poor compatibility or adhesibility to polyester, and cause handling problems during processing. Furthermore, the blockcopolymers containing more than 85 weight percent of polyalkylene ether segments are remarkably inferior in heat stability and chemical resistance.

In most cases, the copolymers containing 8 to 60 weight percent of the ether segments are preferred. In case the ether segment content of the copolymer exceeds 60 weight percent, it is advantageous to mix the copolymer with a fiber-forming polyamide, and compose that mixture with a polyester component, rather than composing the copolymer directly with the polyester component.

The polyalkylene ether-polyamide-block-copolymer can be prepared, for example, by such methods as follows:

(A) Polycondensation of at least one polyamide, precursor, e.g., a lactam, w-amino acid or nylon salt, in the presence of an amino group-terminated polyether or an organic salt thereof.

(B) Polycondensation of at least one polyamide precursor in the presence of a carboxyl group-terminated polyether or an amine salt thereof.

(C) Coupling of a polyether of which two end groups are amino, or carboxyl, or an amino and a carboxyl group, with at least one polyamide oligomer ending with carboxyl groups (when at least one of the polyether end groups is amino) or at least one polyamide oligomer ending with amino groups (when at least one of the polyether end groups is carboxyl), or at least one polyamide oligomer ending with carboxyl and amino groups, in solution or melt form.

As the starting polyether for the preparation of the :block-copolymer, polyalkylene oxides, for example, homopolymers and copolymers of alkylene oxides such as ethylene, propylene, butylene, and tetramethylene oxides can be advantageously used. By cyanoethylation and following hydrogenation of such an alkylene oxide, polyether having two amino end groups is obtained. Also hydrolysis of cyanoethylated alkylene oxide yields, polyether having carboxyl end groups. The preferred degree of polymerization of the starting polyalkylene oxide ranges 20 to 180, particularly, 25 to 140. If that value is less than 20, the resultant 'block-copolymer exhibit poor thermal characteristics. Also if the polymerization degree of polyalkylene oxide is excessively high, the block-copolymer tends to have a lowered adhesibility to polyester. Particularly, it is found that the ether segments in the block-copolymer should be advantageously composed of polyalkylene oxide of a polymerization degree of up to 140, for the preparation of composite fibers of side-by-side structure.

As the polyamide precursor suitable for the preparation of the block-copolymer, the following are the preferred examples: lactams of 6 to 12 carbons, particularly caprolactam; w-aminocarboxylic acids such as 6-aminocaproic, 9-amino-nonanoic, lO-aminocapric, and 11- amino-undecanoic acids, used either singly or as mixture of no less than two components; and nylon salts of hexamethylenediamine or methaxylylenediamine with adipic, sebacic, suberic, and/ or isophthalic acid,

The polyester which is used as an essential component of the composite fibers of this invention include fiberforming homoand co-polyesters composed of a dibasic acid component and a dioxy component, or of oxycarboxylic acid, and modified polyesters containing up to 30 weight percent of other copolymerizable component. For example, polyethylene terephthalate, polyethylene isophthalate, polyethylene terephthalate isophthalate, polyp-ethylene oxybenzoate, polycarbonate, polyethylene adipate, polyethylene terephthalate adipate, and modified polyesters derived from the foregoing may be named. Particularly the modified polyester containing up to 30 weight percent of polyamide blocks is advantageously used as the polyester component of the composite fibers of this invention, because it possesses a better adhesibility to the polyalkylene ether-polyamide-block-copolymer than unmodified polyesters.

The polyester component and polyalkylene ether-polyamide-block-copolymer component composing the composite fibers of this invention may contain conventional additives, such as viscosity stabilizer, antioxidant, stabiliz ing agents against heat and light, delusterant and other pigments, etc. Also each of the compenents may contain starting material (for example, block polyetheramide may contain polyamide and polyether, or block polyesteramide may contain polyamide and polyester). It is again permissible for either of the components to contain polymeric materials other than the starting materials of the component. For instance, the polyalkylene ether-polyamideblock-copolymer may contain polyamide. In fact, the block-copolymer compenent containing more than 60 weight percent of polyalkylene ether segments is first mixed with polyamide to be reduced of its polyalkylene ether segment content to 3 to preferably 8-60% based on the total weight of the mixture, with greater advantage. In that case also the desirable polyalkylene ether segment content of the composite fiber is 0.3-30 Weight percent.

The two or more components of the composite fiber may be present in side-by-side, of core- (or cores-) insheath relationship. The core-in-sheath relationship may be arranged concentrically or eccen-trically. If the corein-sheath structure is employed, even the composite fibers containing a relatively minor amount (e.g., 0.310 weight percent) of polyalkylene ether segments present no operational problem during the processing. Whereas, sidebyside type composite fibers should preferably contain a larger amount (e.g., more than 10 weight percent) of the ether segments.

The composite fibers of the invention can be prepared by the means which are known per se.

In two-component composite fibers, the composing ratio employed is -30 weight percent of the polyester component to the balance amount of the other. Particularly 80-50 weight percent of the polyester component is the range conveniently employed in practice. Also when more than two components are employed, it is suitable to cause the presence of at least 10 weight percent of each component.

Hereinafter numbers of illustrative examples are given for easier understanding of the invention.

The terms used in the following examples have the definitions below.

1) Relative viscosity was measured at 25 C. as to the solution of 1 g. of the sample in ml. of the indicated solvent.

(2) Frictional static charge-Sample (A) (knit piece of filaments) as set on the rotor of a rotary static tester (improved product of Kowa Shokai, Japan), and with the rotation at a fixed speed (800 r.p.m.), frictionally contacted with the object (B) (knit piece of wool). The static charge thereupon built up on the sample (A) was measured. The measuring condition was 20 C. and 65% RH.

(3) Dye absorption-A 0.02% aqueous solution of an acid dye (Xylene Fast Blue PR C.I. Acid Blue 129) of which pH was adjusted to 4 with acetic acid was used as the dyeing solution. Ten (10) grams of sample fibers were put in 1000 ml. of the dyeing solution at 98 C., and dyed for 60 minutes under an agitation at a constant rate. The absorbances of the solution before and after the dyeing were measured with an automatic recording spectrophotometer (product of Hitachi Seisakujo, Japan) and the dye absorption was calculated from the equation below.

Dye absorption (percent) X 100 A absorbance of dyeing solution before dyeing, A absorbance of the solution after dyeing.

level of 100 g./cm. The sample was left under the compressed state for 2 minutes, and then the load was removed at the same rate of exertion. In this operation cycle, the following values were measured to express the compression characteristics of the sample.

Compressive energy (cm.g./cm.

The amount of work required for compressing the fiber mass. This value is correlated with the resistance felt by a person who grips the fiber mass, i.e., stiffness of the fiber.

Recovery energy (cm.g./cm.

The amount of work done by the fiber mass for the recovery from compression. This is correlated with the resilience of the fiber mass.

Resilience (percent) Recovery energy Compression energy 100 Resilience is correlated with liveliness of the fiber mass.

() Crimp characteristics- Number of crimps:

The number of peaks present in mm. of sample fiber which was under a load of 3 mg./d.

Crimp ratio, crimp elasticity:

These values were calculated as follows:

Crimp ratio (percent) =l l /l l 100 Crimp elasticity (percent) =l l /l l 100 1 length of crimped fiber under a load of 3 mg./d.,

1 length of the fiber under a load of 50 mg./d.,

1 length of the fiber after removal of the load of 50 mg./d., when a load of 3 mg./d. was again exerted thereto.

Crimp-elminating load:

The load under which the crimps in the sample fiber completely vanished. Until that point, the load was gradually increased.

All of the foregoing measurements were done in an atmosphere of controlled temperature and humidity of 20 C. and 65% RH.

(6) Equilibrium water content.-The water content at 66% RH, measured by conventional drying method, which was calculated as follows:

Equilibrium water content= W: weight of the sample moistened to equilibrium state, W weight of the dry sample.

The measurement was done at 20 C.

EXAMPLE A (1) Polyethylene glycol diamine (number average molecular weight: approximately 600) of a molecular formula H2NCH2 CHzCHzCHzNHz, was prepared by cyanoethylation and subsequent hydrogenation of polyethylene glycol, was reacted with benzoic acid to form the diamine salt. 8.5 grams of the salt was mixed with 113 g. of anhydrous e-caprolactam, and the mixture was heated to 220 C. in nitrogen current for.

- 6 of the end groups, was reacted with acetic acid to form the diamine salt thereof. 12.7 grams of the salt was mixed with 141 g. of anhydrous -capryl lactam, and the mixture was heated to 220 C. in nitrogen current for 20 hours.

Thus obtained polymer was extracted with hot water for 16 hours. Its relative viscosity in m-cresol was 2.36.

(3) Polyethylene glycol diamine (number average molecular weight: approximately 1150) having two terminal amino groups, which was prepared by cyanoethylation and subsequent hydrogenation of polyethylene glycol, was reacted with equimolar amount of adipic acid to form the diamine salt thereof. 13.0 grams of the salt was mixed with 113 g. of anhydrous e-caprolactam, and the mixture was heated to 240 C. in nitrogen current for 20 hours.

Thus obtained polymer was extracted with hot water for 16 hours. The relative viscosity of the polymer in mcresol was 2.49; amino group concentration thereof was 4.7 10- mol/g., and the carboxyl group concentration was 4.1 X 10* mol/g.

EXAMPLE B (l) Polyethylene glycol di-carboxylic acid having two end carboxyl groups, which was obtained by cyanoethylation of polyethylene glycol (number average molecular weight: approximately 2,000) and subsequent hydrolysis of the product with an aqueous acid, was reacted with equimolar amount of hexamethylenediamine. The resultant salt was mixed with anhydrous e-caprolactam at such a ratio that the salt content of the mixture became 15 weight percent. The mixture was heated to 257 C. in nitrogen current for 15 hours. Thus the object block polyethercapramide was synthesized.

The polymeric product was extracted with hot water for 15 hours. Its relative viscosity in m-cresol was 2.29; amino group concentration was 4.1 10 mol/g; and carboxyl group concentration was 4.5)(10 mol/ g.

(2) A salt composed of a polyethylene glycol dicarboxylic acid (number average molecular weight: approximately 1150) having two carboxyl group and hexamethylene-diarnine was mixed with e-caprolactam. The salt content of the mixture was 15 weight percent. The mixture was heated to 257 C. for 15 hours.

The polymeric product was extracted with hot water. The relative viscosity of the product in m-cresol was 2.31; amino group concentration was 4.7 10-- mol/g; and carboxyl group concentration was 5.3 x10" mol/ g.

(3) A salt composed of a polyethylene glycol (number average molecular weight: approximately 4,800) whose one end group was sealed with an alkyl group and the other end was carboxyl group and m-xylylenediamine, was mixed with e-caprolactam. The salt content of the mixture was 35 weight percent. The mixture was polymerized in the manner similar to the preceding example, and the product was extracted with hot water.

The relative viscosity of the polymer in m-cresol was 2.53; the amino group concentration was 3.9)(10 mol/ g.; and carboxyl group concentration was 4.0x 10* mol/ g.

EXAMPLE C (1) A polyether of the molecular formula H NCH (CH CH O) CH CH CH NH (average value of n: 20.6) which was obtained by cyano ethylation and subsequent hydrogenation of polyethylene glycol, was mixed with a polyamide of the formula OHfCO-(CI-h) NHd- CO (CH 3 CO OH (average value of n: 51.3) which was obtained by polymerization of e-caprolactam with the addition of sebacic acid, at such a ratio that the mol ratio of amino group Before After polymerization, polymerization,

Amino group concentration 2. 95 10- 8. 1X 10- Carboxyl group concentration 2. O1Xl0- 7. 6X10- Melting point: 201 C. Relative viscosity (in m-eresol) 2.25.

(2) A polyether of the molecular formula HOOCt-CH CH' O),,CH CH COOH (average value of n: 15.1) which was obtained by cyanoethylation and subsequent hydrolysis of polyethylene glycol was mixed with a polyamide of the formula (average value of n: 22.3) which was obtained by polymerization of e-caprolactam with the addition of hexamethylenediamine, at such a ratio that the mol ratio of amino group to carboxyl group became substantially 1:1. The mixture was poly-condensed at 220 C. under 3 mm. Hg for hours.

The analytical values of the obtained polymer were as follows:

Before After polymerization, polymerization,

Amino group concentration 4. 1X10- 5. 2X10" carboxyl group concentration 4. 3X10- 5. 1 10 Relative "iscosity (in m-cresol) 2.43

EXAMPLE 1 TABLE I PE 0 segment content of BPE 0 (wt. percent) Relative viscosity in m-cresol oi BPEC EXttillplG No.2

1:11 OTES.B PE C block polyethereapramide; PE 0 polyethylene 0x1 e.

From each of the block polyethercapramides I through X and polyethylene terephthalate (relative viscosity in ochlorophenol: 1.77), side-by-side and core-in-sheath type composite fibers were prepared in accordance with the accepted practice. In the latter type composite fibers, block polyethercapramide was used as the sheath. Spinnability and the characteristics of the so prepared composite fibers are given in Tables II and III.

In Table II-A, the composite fibers of Run Nos. 1, 2, 17 and 18 are not within the scope of this invention. In these fibers, the adhesibility of the components were poor because of excessively low or high polyethylene oxide segment content of the block polyethercapramide. Consequently, their processibility was poor due to the troubles caused by that deficiency. Furthermore, the fibers of Run Nos. 17 and 18 exhibited remarkably inferior chemical resistance.

In the product of Run No. 3, adhesibility of the block polyethercapramide with PET (polyethylene terephthalate) was not very good due to the low PEO (polyethylene oxide) content of the former, but this did not seriously impair the products processibility when the fiber was given a core-in-sheath structure. As to side-by-side structure, however, even the product of Run No. 5 having a somewhat higher PEO content (6 weight percent) showed an inferior processibility. The best processibility was obtained, as to core-in-sheath structure, at the PEO content of BPEC ranging from 3 to 85 weight percent (compare Run Nos. 1 with 3, and 15 with 17), particularly 8 to weight percent (compare Run Nos. 4 with 6, and 11 with 13). As to side-by-side structure, the PEO content ranging from 8 to weight percent (compare Run Nos. 5 with 7, and 16 with 18), particularly 10 to 60 weight percent (compare Run Nos. 7 with 8, and 12 with 14) appears preferable, from the standpoint of both processibility and the properties of the composite fibers obtained.

TAB LE II-A Component of composite fiber First component (block polyether- Ratio capramide) between PEO first and content PEO second in fiber content components (wt. (wt. Second (wt.:wt.) percent) N0 percent) component Composite state 2.0 PET b Core-in-sheath 3:1 1. 5 2. 0 PET b Side-by-side. 3:1 1. 5 4. 0 PET b Core-in-sheath- 3:1 3 6.0 PET .do 2:1 4 6.0 PET b Side-by-Side 2:1 4 9. 0 PET b Core-in-sheath 1:1 4. 5 9. 0 PET b Side-by-side 1:1 4. 5 12.0 PET do 1:1 6 30. 0 PET b Core-in-sheath 1:1 15 30. 0 PET b Side-by-side 1:1 15 54.0 PET b Core-in-sheath- 1:2 18 54. 0 PET b Side-by-side 1:2 18 65. 0 PET b Core-in-sheath 1:2 21. 7 65. 0 PET b Side-by-side 1:2 21. 7 80. 0 PET b Core-in-sheath 1 :3 20 80.0 PET b Side-by-side 1:3 20 90. 0 PET b Core-in-sheath 1:3 22. 5 U0. 0 PET b Side-by-side 1:3 22. 5

Fiber properties Frictional static Strength charge retention Spmnability d Drawabillty Adhesibility d (v.) (percent) Remarks Bun No.:

1 Very good.-- Very poor- Very poor. 2,060 92.5 Processibility poor. 2 Very poor do d0 2, 530 92. 8 Do. 3 Very good. Good do 1, 580 84. 9 4 dn dn Poor 1,100 84. 8 5 Good" Poor. do 1,350 86. 5 Processibility rather poor. 6 Very good.-. Very good Good 1,010 82.6 7 do Goo fi 1,280 84. 5 8 .do Very good. Very good 1, 070 80. 8 9 do do do 640 63. 7 790 64. 3 440 71.0 560 72. 5 370 68. 5 450 71. 0 385 75. 5 475 77. 0 290 72. 3 Poor processibility and chemical resistance. 18 Very poor "do do 370 74. 0 Do.

PEO=polyethylene oxide. b PET=polyethy1ene terephthalate. 0 PET was core, and BPEC was the sheath. d Degree of goodness:

Very good, first grade. Good, second grade. Middle, third grade. Poor, fourth grade. Very poor, fifth grade.

TABLE 11-13 [The data given in this table are those as the eore-in-sheath type composite fibers given in Table II-A] Component of composite fiber First component (block polyethercapramide) Ratio between EPO EPO first and content content second in fiber (wt. Second components (wt. No. percent) component Composite state (wt.:wt.) percent) 2. 0 PET core-in-sheath u-.. 3:1 1. 5 4. 0 PET d 3:1 3 6. 0 PET l 2:1 4 9.0 PET a 1:1 4. 5 30.0 PET 1:1 15 54. 0 PET 1:2 18 65. 0 PET 1:2 21.7 80.0 PET 1:3 20 90.0 PET 1:3 22. 5

Fiber properties Frictional 7 static Strength charge retention Spinnability Drawabiiity Adhesibility (v.) (percent) Remarks Run No.: v

1 Very good.... Very poor-. Very poor 2, 060 92. 5 Processibihty poor. 3 do.......-. Good do 1, 580 84. 9 0.. Poor 1,100 84.8 Very good Good. 1, 010 82.6 do Very good..- 640 63. 7 do (in 440 71. 0 370 68. 5 385 75. 5 17 Middle Very poor Very poor.. 290 72.3 Poorprocessibihty and chemical resistance.

PET=polyethylene terephthalate. b PET was the core, and BPEC (block polyethercapramide) was the sheath.

TABLE 11-0 [The data given in this table are those as to slde-by-slde type composite fibers given in Table II-A] Component of composite fiber Ratio First component of first Fiber properties (B EC) e component to second PEO Fric- PEO b component content tional content (PET) in fiber static Strength (Wt. (wt. (wt. charge retention No. percent) percent) percent) Spinnability Drawability Adhesibility (v.) (percent) Remarks 2. 3:1 1. Very poor Very poor Very poor 2, 530 92. 8 Processibility poor. 6. 0 2:1 4. 0 Good Poor Poor 1, 350 86. 5 Processibility rather poor. 9. 0 1:1 4. 5 Very good... Good Good 1, 280 84. 5 12. 0 1:1 6.0 d Very good..." 1,070 80.0 30.0 1:1 15.0 (10......... 790 64. 3 54. 0 1:2 18.0 560 72. 5 65. 0 1:2 21. 7 450 71.0 80. 0 1 :3 20. 0 475 77. 0 90. 0 1:3 22. 5 370 74.0 Poor processibility and chemical resistance.

: BPEC =Block polyethercapramide. b PEO =polyethylene oxide. PET =polyethylene terephthalate.

Table III is given for the purpose of illustrating the significance of polyethylene oxide segment content of the composite fiber.

The core-in-sheath type composite fiber of Run No. 1 is outside the scope of this invention, which exhibited poor antistatic property (above 3,000 v.) and poor processibility, due to the excessively low polyethylene oxide segment content.

Although Run No. 6 belongs to the scope of the invention, the product side-by-side composite fiber had a somewhat inferior antistatic property to that of core-in-sheath type fiber. Therefore, for side-by-side structure, it is desirable for the fiber to contain no less than 1.0 weight percent of polyethylene oxide.

The polyethylene oxide segment contents of the products of Run Nos. 5 and 10 exceeded the upper limit specified in this invention. As indicated in the table, the prod- O ucts had poor heat resistance, substantiated by poor strength retention (below 60% The polyethylene oxide content of the composite fiber which will give good processibility as well as good fiber properties, ranges from 0.3 to 30 weight percent (cf. Run

7, 8 and 9, 10) for side-by-side structure.

Drawability Fiber properties Frictional static Strength charge retention Run No.:

............ Very poor Very poor Adhesibility (v.) (percent) Remarks 3,450 98. 0 Poor antistatic property. 2, 970 96. 5 2, 200 94. 2 200 60. 3 55. 1 Poor heat resistance. 3, 350 9G. 8 Poor antistatic property. 2, 910 94. 3 2, 750 92. 8 250 61. 2

56. 2 Poor heat resistance.

13 EXAMPLE 2 TABLE IV Average recurring unit number PEO segment Relative of E in content of viscosity PEO segment BPEC (wt. in rn-cresol in BPEC percent) of BPEO N ore-E O=ethy1ene oxide.

Separately, four types of block polyesteramides as listed in Table V below were prepared from a polycapramide of molecular weight of approximately 5,000 and a polyethylene terephthalate (PET) of a molecular weight of approximately 10,200.

TAB LE V C opolymer composition Relative PE viscosity polycapramide of copolymer in (wt./wt.) o-chlorophenol From each of the block polyethercapramides A-I through A-VIII and a polyethylene terephthalate which had a relative viscosity in o-chlorophenol of 1.73, side-byside and core-in-sheath composite fibers were prepared by the means known per se.

Also from the block polyethercapramides IV and IX and the block polyesteramides B-I through B-IV, side-byside composite fibers were prepared by the means known per se (Run Nos. 9-13).

From the block polyethercaprarnide IV and the block polyesteramides B-I through B-IV, core-in-sheath type composite fibers were prepared by the means known per se (Run Nos. 22-25).

The spinnability and the properties of the composite fibers obtained in each run are shown in Table VI.

In Table VI, the products of Run Nos. 1, 8, 14 and 21 exhibited satisfactory properties, but the operability of composite fiber preparation from block polyethercapra- *mide A-I or A-III and polyethylene terephthalate was somewhat interior. The processibility depends on the recurring unit number of ethylene oxide in the polyethylene oxide segment of block polyethercapramide. Accordingly, the preferred recurring unit number ranges approximately 20-180 (compare Run Nos. 1 with 2, 7 with 8, 14 with 15, and 20 with 21), and the optimum range appears to be 25-140 (compare 'Run Nos. 2 with 3, 5 with 6, 15 with 16 and 18 with 19).

Run Nos. 9-13 and 22-25 are the examples in which modified polyesters were used as a component of composite fibers. The products of Rum Nos. 13 and 25 are objectionable in that their initial modulus was extremely low, due to the excessively large amount of polyamide segments in the block polyestera-mide employed.

For a polyamide-modified polyester to exhibit the adhesibility and dyeability-improving eifect, when used as a component of composite fibers, without appreciably detrimental eifect on other fiber properties, its polyamide segment content must not exceed the upper limit of 30 weight percent (compare Run Nos. 12 with 13, and 24 with 25). Particularly, the optimum polyamide segment content ranges from 10 to 30 weight percent. As indicated by the result of Run No. 12, when such a modified polyester is /5 1.87 used as the polyester component, even the block polyethergg capramrde containing 8 weight percent of polyethylene 65/35 1. 93 45 oxide can be satisfactorily combined therewith to form s1de-by-s1de composlte fibers.

TABLE VI Components of composite fiber First component (block polyether- Ratio eapramide) between PE 0 the first content Number of and second of fiber recurring Second component (composition component (wt. No. unit of E0 of copolymer) Composite state (wt.:wt.) percent) A-I 15 PET Side-by-srde 1:1 12 A-II 21 PET (1 1:1 12 A-III 30 PET 1:1 12 A-IV 64 PEl 1:1 12 A-V PET 1:1 12 A-VI PET--- 1:1 12 A-VII PET 1:1 12 A-VIII 200 PE T 1: 1 12 A-IV 64 Block polyesteramid 1:1 12 A-IV 64 Block polyesteramide: II. 85/15 1:1 12 A-IV 64 Block polyesteramide:B-111, 75/2 1:1 12 A-IX 64 Block polyesteramidezB-lll, 75/2 1:1 4 A-IV 64 Block polyesteramidezB-IV, 65/35 1:1 12 A-I PET 1:1 12 A-II 1:1 12 A-III 1:1 12 A-IV 1:1 12 A-V 1:1 12 A-VI 1:1 12 A-VII 1:1 12 A-VIII 200 PET. 1:1 12 A-IV 64 Block polyesterami 1 1:1 12 A-IV 64 Block polyesteramidezB-II, /15 1:1 12 A-IV 64 Block polyesteramidezB-III, 75/25 1:1 12 25 A-IV 64 Block polyesteramidezB-IV, 65/35 do 1:1 12

TABLE VIContinued Fiber properties Frictional static Dye Initial charg absorption modulus Spninability Drawability Adhesibility (v.) (percent) ./d.) Remarks 1, 320 68. 2 43. 2 Proeessibility rather poor. 1, 100 67. 5 52. 6 950 67. 5 56. 5 910 65. 4 60. 3 870 64. 9 65. 5 860 59. 7 66. 8 950 59. 1 67. 5 1, 020 57. 3 65. 3 Proeessibllity rather poor. 950 67. 5 56. 3 830 70. 3 50. 5 740 72. 6 39. 8 1, 290 78. 5 45. 3

630 76. 3 28. 5 Initial modulus low. 1, 040 70. 5 43.8 Processibility rather poor. d d 890 G9. 8 53. 6 16 ..do Very good-.. Very 770 71. 56. 3 dod 740 70.8 61. 5 710 70. 1 66. 3 695 67. 3 67. 8 780 68. 1 67. 3 860 66. 5 66. 4 Processibility rather poor. 750 70. 6 57. 3 680 78. 5 51. 5 600 82. 6 38. 7 540 88. 6 29. 3 Initial modulus low.

Core EXAMPLE 3 The salt of a diamine derived from a polyethylene glycol (number average molecular weight: approximately 4,800) and adipic acid by the procedure described in Example A(3) was mixed with e-caprolactam at such ratios that the copolymers polyethylene oxide segment contents should become the values indicated in Table VII. The mixtures were polycondensed and processed in the accepted manner. Thus block polyethercapramides I through IV as listed in the same table were obtained.

TABLE VII PEO segment Relative content of viscosity BPEC (wt. oiBPEC percent) m-cresol Each of the block polyethercapramides I through IV was mixed with a polycapramide having a relative viscosity in m-cresol of 2.49. Each of the mixtures was used to form side-by-side and core-in sheath composite fibers, together with a polyethylene terephthalate having a relative viscosity in o-chlorophenol of 1.75.

The spinnability and the properties of the composite fibers obtained in each run are shown in Table VIII.

-in-sheath structure: PET was the core and BPEC was the sheath.

In Table VIII-A, the filamemnts of Run Nos. 1, 2, 17 and 18 are outside the scope of this invention. Their adhesibility were poor due to the excessively high or low polyethylene oxide segment contents of the mixtures of the block polyethercapramide and polycapramide. And, due to the troubles caused by the poor adhesibility, their processibility was also poor. Again the fibers of Run Nos. 17 and 18 exhibited poor chemical resistance.

The adhesibility of the components employed in Run N0. 3 was not very good due to the rather low polyethylene oxide segment content of the mixture, but it was not a very serious problem in the preparation of core-in-sheath composite fiber. In contrast, in the preparation of side-byside composite fiber, local separation of the two components during drawing was observed even when the polyethylene oxide content of the mixture was 6 weight percent (Run No. 5).

The processibility depends on the polyethylene oxide segment content of the mixture of block polyethercapramide and polycapramide. In the case of core-in-sheath type fibers, the range of 3-85 weight percent (compare Run Nos. 1 with 3, and 15 with 17), particularly 8-60 weight percent (compare Run Nos. 4 with 6, and 11 with 13) appears to be appropriate. As to side-by-side structure, that of 8-85 weight percent (compare Run Nos. 5 with 7, and 16 with 18), inter alia, 10-60 weight percent (compare Run Nos. 7 with 8, and 12 with 14) is preferred.

TABLE VIII-A Component of composite fiber First component (mixture otbloek polyethereaproamide and polycapramide) Ratio PEO between PEO content the first content of mixand second of fiber ture (wt. Second component (wt Mixing ratio (BPECzPCA) percent) component Composite state (wt.:wt.) percent) BPEG (24%):PPCA, 1:9 2.4 PET Core-in sheath 2:1 1, 6 BPEC(24%):PCA, 1:9 2.4 PET Side-by-side 211 1.6 BPEC(24%) :PCA, 1:5 4. 0 PET Core-in-Sheath 2: l 2. 7 BPEC (24%): C 1:3 6.0 PET o 2:1 4. 0 BPEO (24%):PCA, 1:3 6. 0 PET Side-by-s1de 2:1 4. o BPEC (24%):PCA, 1:1.5 9. 6 PET Core-in'sheath- 2:1 6. 4 BPEC (24%):PCA, 1:1.5 9. 6 PET Side-by-side. 2:1 6.4 BPEC (24%):PCA,1:1 12.0 PET .do 11 6.0 BPEC (64%) :PCA, 1:1 32. 0 PET Core-in-sheath 11 16.0 BPEC (64%):PCA, 1:1 32.0 PET S1de-by-Side 1:1 16.0 BPEO :PCA, 2:1 53. 3 PET Core-in-sheath- 1:2 17. 8 BPEO (80%):POA, 2:1 53. 3 PET Side-by-side 1:2 17.8 BPEC (80%):PCA, 4:1 64.0 PET Core-in-sheath- 1:2 21. 3 BPEC (80%):PCA, 4:1 64. 0 PET Side-by-side 1:2 21. 3 BPEC :PCA, 5:1 75. 0 PET Core-in-sheath- 1:2 25. 0 BPEC (90%) :PCA. 5:1 75. 0 PET Side-by-side 1:2 25. 0 BPEC (90%) :PCA, 10:1 85. 5 PET Core-in-Sheath- 1:2 28. 5 18 BPEC (90%):1CA, 19:1 85.5 PET Side-by-side 1:2 28,5

Processibility poor:

Processibility poor.

Processibility and chemical resistance poor. 7 Do.

Ratio between PEO the first content and second of fiber component (wt. (wt.:wt.) percent) TABLE VII IAComtinued Fiber properties Frictional static Strength charge retention Spinnabihty Drawabihty Adhesibihty (v.) (percent) Remarks Good. Very poor-.." Very poor Very poor do Very good"-.. Good. do

ood dn do 3 1% y good Very good .rin do "110... 13 do Good- .do. 14 Good .do d0 J10 Middle Middle dn do Very poor Very poor.-."

Very poor do 0 0-10 62.

pramide was 24 wt. percent PCA polycapramide. lPCA was the sheath.

TABLE VIII-B [Among the data given in Table III-A, those on core-in-sheath structure fibers only are extracted in this table] Component of composite fiber First component (mixture of block polyethercaproamide and polycapramide) PEO content of mixture (wt. Second percent) component Composite state 24%) means that PEO content of block polyetherca -in-sheath structure: PET was the core and BPEO Mixing ratio (BPEC :1? CA) do. Very good Ver c Very good Ver NOTE.BPEC/PCA means the mixture of BPEC and PCA.

BPEC Core Run No.:

Run No.:

chemical resistance poor.

n BPEC (24%) means that PEO content of block poiyethercapramide and 24 wt percent. PCA polycapramide. b Core-insheath structure: PET was the core and BPEC/P CA was the sheath Ratio between PEO content of fiber (wt. percent) Fiber properties Frictional static Strength charge retention (v.) (percent) Remarks Processibility poor.

Processibility and the first and second component Composite state (wt.:wt.)

Second percent) component Spinnability Drawability Adhesibiiity Very poor Very poor Good TABLE VIII-C [Among the data given in Table VIII-A, those on side-by-side structure fibers only are extracted in this table] Component of composite fiber First component (mixture of block polyethercaproamide and polycapramide) ture (wt. Mixing ratio (BPEC:P CA) Good Run No.:

TABLE VIIICContin11ed Fiber properties Frictional static Strength charge retention Spinnabllity Drawabllity Adhesibiiity (v.) (percent) Remarks Run No.:

2 Very poor Very poor... Very poor"..- 930 92.6 Processibility. 5 Good Poor Poor 730 86.9 Do.

Very good.-." Good G 480 84.3 do Very 515 81.5 138 82.6 125 79.3 70 74.8 30 70.1 -10 62. 7 Processibility and chemical resistance poor.

B BPEC (24%) means that PEO content of block polyethercapramide was 24 wt. percent. The significance of polyethylene oxide segment content TABLE x of composite filters is illustrated in Table IX. Average The composite fibers obtained in Run Nos. 1 and 6 exnumb" E0 recurring PEO segment Relative hibited rather poor processibility, because of the poor mun PEO content or viscosity adhesibility of the components due to the low poly- Segment BPEC MBPEG fBPE t 1 1 ethylene oxide segment contents of the fibers. Whereas, o O percen) nmmso excessively high polyethylene oxide content causes poor 15 48 2.35 heat resistance as indicated by the unsatisfactory strength 1g 2g retention (below 60%) of the products of Run Nos. 64 48 2:40 and 10. P 33 g-g;

55 From the results given 1n Table IX, the preferred range 170 48 2. 38 200 48 2. 41

of polyethylene oxide content of the fibers as to each structure appears to be as follows:

Core-in-sheath structure- 0.3-30 weight percent (cf. Run Nos. 1, 2 and 4, 5), particularly 0.8-30 weight percent (cf. Run Nos. 2, 3 and 4, 5

Side-by-side structure- Separately, from a polycapramide of a molecular 30 weight of approximately 3,200 and a polyethylene ter- TABLE XI Composition 01 Relative of copolymer viscosity of (PET/polycopolymer in eapramide wt./wt.) o-chlorophenol 0.8-30 welght percent (cf. Run Nos. 6, 7 and 9, par- 2%? 3 ticularly 1.0- welght percent (cf. Run Nos. 7, 8 and /25 1, 9, 65/35 1.94

TABLE IX Component of composite fiber First component (mixture of block polyethercaproamide and polycapramide) Ratio PEO between PEO content the first content of and second of fiber Mixing ratio ture (wt. Second component (wt. (BPECzPCA) percent) component Composite state (wt.:wt.) percent BPEC(24%):PCA, 1:9 B 2.4 PET Core-ln-sheath 1:9 0. 24 BPEC(24%):PCA, 1:3 6.0 PET .--.-d0 1:9 0.6 PEC(24%):POA, 1:1 12.0 PET 129 1.2 BPEC(64%):PCA, 1:1 32.0 PET 3:1 24. 0 BPEC(%):PCA, 1:1 40.0 PET 4:1 32. 0 BPEC(24%):POA, 1:3 6.0 PET 1:9 0. 6 BPEC(24%):PCA, 1:2 8.0 PET 1:8 0.89 BPEC(24%):PCA, 1:1 12.0 PET 1:9 1. 2 PEO(64%):PCA, 1:1 32.0 PET 3:1 24.0 BPEC(80%):PCA, 1:1 40.0 PET 4:1 32.0

Fiber properties Frictional Strength atic retention st Spinnability Drawability Adheslbility charge (v.) (percent) Remarks Run N0.:

1 Middle Very poor..... Very poor..-" 1, 320 96. 8 Processlbility poor. 2 Very good Good Poor 1, 200 96. 2 980 94. 6 20 62. 3 0-10 41. 5 Heat resistance poor. 1, 500 97. 2 Proccssibllity poor. 1, 440 95. 3 1, 320 92. 1 35 66. 5 010 45. 3 Heat resistance poor.

' BPEO (24%) means that PEO content of block polyethercapramide was 24 wt. percent PCA polycapramide. h Core-in-sheath structure: PET was the core and BPEC/PCA was the sheath.

EXAMPLE 4 Eight (8) types of block polyethercapramides were synthesized by the procedures described in Example A(3) as in the following Table X.

Using a mixture of each of the block polyethercapramides A-I through A-VIII and a polycapramide having a relative viscosity in m-cresol of 2.38 as the first com- 5 ponent, and a polyethylene terephthalate having a relative viscosity in o-chlorophenol of 1.73 as the second component, side-by-side and core-in-sheath type composite fibers were prepared in the accepted manner (Run Nos. 1-8 and 13-20).

Separately, from the mixture of block polyethercapramide A-IV and the polycapramide as the first component and each of the block polyesteramides B-I through B-IV as the second component, side-by-side and core-in-sheath structure composite fibers were prepared in the accepted manner (Run Nos. 9-12, and 21-24). The spinnability and the properties of the product of each run are shown in Table XII.

In the same table, the products of Run Nos. 1, 8, 13 and 20 exhibited satisfactory properties, but the processibility was somewhat inferior in the cases of employing the mixture of either block polyethercapramide A-I or A-VIII and the polycapramide, and the polyethylene terephthalate.

The processibility depends on the number of ethylene oxide recurring units in the polyethylene oxide segment of block polyethercapramide. From the empirical results, the recurring unit numbers of approximately -180 (compare Run Nos. 1 with 2, 7 with 8, 13 with 14, and 19 with 20), particularly -140 (compare Run Nos. 2 with 3, 5 with 6, 14 with 15 and 17 with 18) appear to be the most advantageous.

Among the runs employing the modified polyesters as one of the components of the fibers, Run Nos. 12 and 24- yielded the fibers of extremely low initial modulus due to the excessively high polyamide segment content of block polyesteramide.

The upper limit of the polyamide segment content of modified polyester for exhibiting the adhesibilityand deyability-improving effect without appreciable detrimental effect on other properties is weight percent. Particularly 10-30 Weight percent is the optimum range.

TABLE XII Component of composite fiber Ratio Second between PE 0 component the first content First component (mixture of (composiand second of fiber BPEC and polycapramide) tion of components (wt. mixing ratio (wt.: wt.) copolymer) Composite state (wt.: wt.) percent) BPEC( l:n=l5): PCA, 1:1 PET Side-by-side 1:1 12 BPEC(n=21):PCA, 1:1 PET 1:1 12 BPEC(Pn=30) :PCA, 1:1 PET 1:1 12 BPEC(Pn=64)PCA, 1:1 PET 1:1 12 BPEC(Pn=):PCA, 1:1 PET 1:1 12 BPEO(gn=):POA, 1:1 PET 1:1 12 BPEC( I n=) :PCA, 1:1 PET 1:1 12 BPEC(En=200):POA, 1:1 PET 1:1 12 BPEC(En=64):PCA, 1:1 B-I 95/5 1:1 12 BPEC(Pn=64);PCA,1:1 B-II 85/15 1:1 12 BPEC( I:n=64):POA, 1:1 B-III 75/25 -do.- 1:1 12 BPEC(EI1=64) :PCA, 1:1 B-IV 65/35 1:1 12 BPEC(Pn=15) :PCA, 1:1 PET Core-in-sheath b 1:1 12 BPE0 n=u =PoA, 1:1 PET d0 1:1 12 BPEC(n=30):PCA, 1:1 1:1 12 BPEC( I n=64):PCA, 1:1 1:1 12 BPEC(En=125):PCA, 1:1 1:1 12 BPEG( l:n=l55) :PCA, 1:1 1:1 12 BPEC( Pn=170):POA, 1:1 1:1 12 BPEC(Pn=200):PCA, 1:1 1:1 12 BPEC(gn=64):PCA, 1:1 1:1 12 BPEO(En=64):PCA, 1:1 1:1 12 BPEC(En=6'1):PCA, 1:1 1:1 12 24 BPEC(Pn=64):POA, 1:1 1:1 12

Fiber properties Frictional static Dye Initial charge absorption modulus spinnability Drawability Adhesibility (v.) (percent) (g./d.) Remarks lfg Good Poor Good 291 66. 3 49. 5 Processibility rather poor. 2 '"a its; 23% 2%? V 6..... Ver oo er 0o enhgoo 258 62. 1 67. 8 5 do do do 258 61. 3 72. 1 6..-- ,dn dn do 260 59.2 69.5

Good Good. Good.-. 280 56. 3 69. 8 8 Poor. Poor- Poor. 285 54. 2 68. 5 Processibillty v d 23s 65 3 57 3 rather poor' 9 V r ood Ve ood.. ery goo in e do 208 68.1 51.3 11 do ..do do 188 70. 8 39. 6 12 (in dn do 159 74. 1 29. 9 lnlitial modulus ow. 13 (in Poor Good 245 70. 1 50. 1 Processibility rather poor. 14 do Go0d .d. ndmu ufldo Ve o0 I cry goo 1 2 (in do 200 68. 3 66. 8 205 67. 6 74. 6 210 65.3 72. 8 235 65. 4 73. 5 245 63. 2 70. 4 Processibility rather poor. 70. 8 58. 3 163 75. 3 53. 3 23 rln do (in 152 78. 5 40. 8 24- do dn do 120 82. 6 28. 1 lnlltial modulus 8 B PE 0 (Pn= 15) indicates that the number of E O recurring units in PE 0 of B PE 0 is 15 (P CA is polycapramide) b PET was the core and BPEC/PCA was the sheath.

23 EXAMPLE A polyethylene oxide diamine having amino groups at its both ends was synthesized by cyanoethylating a polyethylene glycol (number average molecular Weight: approximately 4,200) and further hydrogenating the same. Then the diamine was reacted with equimolar amount of adipic acid to form a diamine salt. The salt was mixed with e-caprolactam at such ratios that the polyethylene oxide contents of the mixtures should become the predetermined values, and the mixtures were heated at 240 C.

TAB LE X lV Components of composite filaments Ratio PEO Equi- Crimp properties between content Frielibrium the first of lilational water Dye Number Crimp Second and second ment static content absorpo1 crimps eliminat- First component comcomponents (wt. charge (wt. tion (peak/ ing load (BPEC) poncnt (wt.:wt.) percent) (v.) percent) (percent) 25 mm.) (g./d.) Remarks Run No 1 Block poly-ether- PET 50:50 4. 0 1, 350 3. 91 59. 5 33. 0 0. 100 Side-by-side adhecaprainide. sibility rather poor.

50:50 8.0 1, 030 4. 60 61. 8 54. 8 0.098 Side-by-side adhesibility passable. 33:07 5. 3 950 3. 13 30. 5 13. 5 0.114 Core-in-sheatlt 50:50 12. 0 880 5. 66.3 G0. 3 0. 095 Side-by-side adhesibility good. 33:67 7. 9 1, 530 3. 70 41. 5 15. 8 0. 109 Core-in-Sheath 50 16.0 630 6. 28 68. 5 75. 9 0.084 Side-by-side adhesibility good.

7 Copolyester PET 50:50 0 3, 740 0.67 24. 3 21. 8 0. 085 Side-hy-side adhesibility good, control.

8 PET 0 3, 980 0. 48 21.0 Control.

Polyethylcne terephthalate.

PEI was the core.

Block polyethercapramide was the core.

Polyethylcne terephthalate/polyethylene isophthalatc, 00/10.

TABLE XIII PE 0 Relative content of viscosity BPEC (ct. o1 BPEC percent) in m-cresol Using each of the above four block polyetheramides with a polyethylene terephthalate having a relative viscosity in o-chlorophenol of 1.79, side-by-side (Run Nos. 1, 2, 4 and 6) and eccentric core-in-sheath (Run Nos. 3 and 5) composite fibers were formed in the accepted manner. The spinning temperature employed was 290300 C. at the cylinder portion, and 285-295 C. at the pump portion, with the slight variations depending on the specific block polyetheramide. The winding speed was 425 m./min. The spinnability was good with all runs, and filament bending at the face of the spinnert was hardly observed. The undrawn filaments were drawn 3.5 x in the accepted manner, with a hot pin of C. and hot plate of 145 C. The adhesibility of the drawn filaments were good in all runs except Run No. 1 in which the block polyetheramide I was used. The products of all runs except Run No. 1 exhibited no separation of individual components after repetitive exertion of tension of 500 times. The product of Run No. 1 showed partial com- The results given in Table XIV indicate that the filaments of this invention possess better antistatic property, dyeability and hygroscopicity, than the two control products (Run Nos. 7 and 8). Inter alia, the core-in-sheath structure composite filament in which the block polyethercapramide Was the sheath (Run No. 3) showed extremely good antistatic property. Also the filaments of the invention had an improved hand, unlike the stiff hand of polyethylene terephthalate fiber.

EXAMPLE 6 In the similar manner to Example 5, four block polyethercapramides identified in Table XV were synthesized.

Using each of the above block polyethercapramide and a polyethylene terephthalate having a relative viscosity in o-chlorophenol of 1.75, side-by-side type composite filaments Were prepared in the manner described in Example 5. All of thus obtained drawn composite filaments developed coil-formed crimps when freed from tension. The fiber quality of the products are shown in the following Table XVI, together with the results of two control runs (Run Nos. 5 and 6).

TABLE XVI Components of composite fiber PEO content Frictional Ratio between the of fiber static Second first and second (wt. charge First component component components (wt.:wt.) percent) (v.)

Side-by-side 50:50 12 880 do 12 870 12 1, 010 12 1, 090 3, 760 0 3, 940

Crimp characteristics Tensile properties Number Dye of crimps Crimp Crimp Crimp Initial absorption (peak/ ratio elasticity eliminating Strength Elongation modulus (percent) 25 mm.) (percent) (percent) load (g./d.) (g./d.) (percent) (g./d.)

* Polyethylene terephthalate.

b A copolymer of polyethylene terephthalate/polyethylene isophthalate, 88/12.

So far as our experiments confirmed, the adhesibility of the two components was excellent with the block polyetheramides III and IV having short polyether segments. However, from overall characteristics of the filaments, use of block polyetheramides containing the polyetheramide segments of the molecular weight ranging 2,000-6,000 gave the optimum results.

EXAMPLE 7 Separately, a minor amount of a polymerization catalyst was added to p-(B-oxyethoxy)methyl benzoate, and

the mixture was first subjected to a prepolymerization by heating at 180220 C. for 3 hours at atmospheric pressure. Then the temperature was raised to 250 C., and polymerization was continuously performed under a reduced pressure of 0.2 mm. Hg for 10 hours. Thus obtained polymer was extruded into a form of gut, and then cut into chips. The relative viscosity of the polymer in o-chlorophenol was 1.89.

Using each of the above block polyetheramides and the poly-p-ethylene oxybenzoate, side-by-side type composite drawn filaments were prepared in the manner described in Example 5. The adhesion between the two components was good, and none of the products showed any separation after 500 times repetitive exertion of tension. The

properties of the drawn filaments are shown in Table XVIII. Also for comparison, the properties of a composite filament prepared from two poly-p-ethylene oxybenzoates of different viscosities (relative viscosities in o-chlorophenol:1.89 and 1.71) are shown in the same table.

TABLE XVIII Components of composite filament Polyethcr content of Ratio between the first filament Frictional and second components (Wt. static First component Second component (Wt.:wt.) percent) charge (v.) Run No.:

1 BPEC I Poly-p-ethylene Side-by-side, :50 8.0 1,230

oxybenzoate. BPEC II .do do 12.0 1,030 BPEC III 16.0 960 Poly-p-ethylene 0 3, 850

oxybenzoate.

Crimp characteristics Tensile properties Number Dye oi crimps Crimp Crimp Crim Initial absorption (peak/2 ratio elasticity eliminating Strength Elongation modulus (percent) mm.) (percent) (percent) load (g./d.) (g./d.) (percent) (g./d.)

59. 3 39. 1 40. 5 77. 5 0. 083 3. 2G 29. 9 45. 5 61. 5 4s. 3 51.8 76. 1 0.087 2.98 31. 5 41. 8 63. 5 56. 1 58. 3 73. 8 O. 081 2. 85 30. 8 37. 9 22. 1 18. 5 20. 7 88; 1 0. 121 3.65 33. 2 s2. 3

C. for 12 hours to be removed of the unreacted com- EXAMPLE 8 pgnents. 'ghilpgzpflrltiteslof the block polyethera are A block polyethercapramide of which polyethylene 5 own 111 a e e oxide segment content was 45 weight percent was syn- TABLE XVII thesized from a polyethylene glycol (number average Polypropylene molecular we1ght:approx1mately 4,400) in the manner g g ggt $2232 descrlbed in Example 5. The relative viscoslty of the BPEC (wt E, polymer in m-cresol was 2.49. Mixtures of this block polyp in m-cresol ethercapramide and a polycapramide having a relative Nulilber ofBPEC: 16 0 2 69 viscosity in 98% sulfuric acid of 2.65 were used as the first components in the experiments, and a polyethylene II terephthalate having a relative viscosity in o-chloropheno] of 1.78 was used as the second component, to form sideby-side and core-in-sheath structure composite filaments. The spinning and drawing operations were similar to those described in Example 5. The products exhibited excellent antistatic property. The properties of the products are shown in Table XIX.

content was 45 weight percent was synthesized from a polyethylene glycol (number average molecular weight: approximately 4,100) in the similar manner described in Example 5. The polymer had a relative viscosity of 2.51 in m-cresol.

A chip mixture of the block polyethercapramide and a TABLE XIX Crimp characteristics PEO Filament component content of Frictional Number filament static of crimps Crimp Crimp First component (by Ratio between first and second component (wt. charge (peak/ elasticity eliminating weight) (\vt.:\vt.) percent) (v.) 25 mm.) (percent) load (g./d.)

Eccentric core-in-sheath 50:50 4. 5 5 0 15. 1 79. 8 0. 001 Concentric core-in-sheath 50:50-- 4. 5 920 0 Eccentric core-in-sheath -65 1. 6 1, 520 9. 7 83. 1 0. 008 Side-by-side, 50:50 l1. 5 260 36. 8 76. 8 0. 101 Side-by-side, 50:50 13. 5 200 38. 5 74. 0 0. 080

e PET was the core. b Mixture of BPEC and PCA (polycapramide) were the cores.

EXAMPLE 9 A block polyethercapramide of which polyethylene oxide polyamide having a relative viscosity of 2.68 in 98% sulfuric acid was used as the first component, which was 35 spun into composite filaments together with the poly-pethylene oxybenzoate prepared in the manner similar to Example 7. Thus in the manner similar to Example 5, eccentric and concentric core-in-sheath structure composite drawn filaments were prepared. The products exhibited excellent antistatic property. The properties of the products obtained are shown in Table XX, together with the properties of the filaments from poly-p-ethylene oxybenzoate alone as control.

TABLE XX Filament component PE 0 content First component Ratio between the of fila- (sheath) (mixture of Second component first and second merit (wt. BPEC and PCA) (core) component (wt.:wt.) percent) Run No.:

1 BPECzPCA, 20:80 Poly-p-ethylene- Eccentric eore-in- 4, 5

oxybenzoate. sheath, :50. 2 BPECzPCA, 20:80 do Eccentric core-in- 3.2

sheath 35:65. 3 BPEO:PCA,10:90 do do 1,5 4 BlECzPCA, 20:80 .do Concent 4. 5

sheath, 50:50. 5 BPECzPCA, 20:80 d0 Concentric core-in- 1.8

sheath, 20-80 6 Poly-p-ethylene oxybenzeate alone. Crimp characteristics Tensile properties Friction Number stat of crimps Crimp Crimp Initial charge (peak/ elasticity eliminating Strength Elongation modulus (v 25 mm.) (percent) (g./d. (g./d.) (percent) (g./d.)

31 The mixture was dried, and subjected to a solid phase polymerization at 200 C., under a reduced pressure of 0.5 mm. Hg for -16 hours. Thus modified polyesters in which the polyester component and polyamide component were combined in block forms (hereinafter the modified polyesters will be referred to as block polyesteramides) were obtained. The particulars of the block polyesteramides are shown in Table XXIII.

TABLE XXIII Number Number average average molecular molecular Relative visweight of weight of Composition cosity oi block N o. of starting starting eopolymer polyesteramide block polypolyester polyamide polyester] in o-chloro esteramide component component polyamide phenol Various composite drawn filaments were prepared from the above five block polyesteramides, and block polyetheramides, or mixtures of block polyetheramide with polycapramide, as indicated in Table XXIV. Block polyesteramide exhibited better adhesibility to block polyetheramide than unmodified polyester, for example, polyethylene terephthalate. Therefore, in the case of core-insheath structure, thinner sheath may be employed. As to side-by-side structure, while in Example 5 the block polyethercapramide (PEO segment content: 8 weight percent) and polyethylene terephthalate showed partial separation or peeling off during the stretching, the replacement of polyethylene terephthalate by the block polyesteramide as done in this example eliminated such fated defect.

5 content of the copolymer being 3 to 85% by weight, and the polyalkylene ether segment content of the composite fibers being 0.3 to 30% by weight.

2. The composite fibers of claim 1, in which the polyalkylene ether segment content of the polyether-polyam- 0 ide-block-copolymer is 8 to 60% by weight, the polyalkylene ether segment content of the fibers is 0.8 to 30% by weight, and the average recurring unit number of the alkylene oxide forming the polyalkylene ether segment is to 180.

15 3. The composite filament of claim 2 in which the average recurring unit number of the alkylene oxide forming the polyalkylene ether segment is to 140.

4. The composite filament of claim 1 in which the polyester component is a block-polymer consisting of polyester segments and linear polyamide segments, the polyamide segment content of the block-copolymer being 030% by weight.

5. Composite fibers in which as least two polymeric components are arranged in intimate mutual contact and in side-by-side relationship along the fiber length, and at least one of the said components is a fiber-forming polyester, and the other of the said components is a polyether-polyamide-block-copolymer consisting of linear polyamide segments and polyalkylene ether segments, the

polyalkylene ether segment content of the block-copolymer being 8 to 85% by weight, and the polyalkylene ether segment content of the fibers being 0.8 to 30% by weight.

TABLE XXIV Components of composite filament PE 0 Second content component Ratio between the of fila- (block polyfirst and second ment (wt. First component BPEC esteramide) components (wt.:wt.) percent) Side-by-side, 50:50. 12. 0 o 12.0 Core-in-sheath b 3. 6

(concentric), 15:85. 4 BPEC II II Core-ln-sheath, 15:85. 3.6 Mixture of BPEC III and PCA, IV Side-by-side (concen- 15. 0

66:34 (by weight). tric), 50:50. 6 Mixture of BPEC III and PCA, IV Core-in-sheath b 3.0

34:66 (by weight). (concentric), 20:80. 7 Mixture of BPEC III and PCA, I Core-in-sheath b 3. 6

20:80 (by weight). (concentric), :60.

Equi- Crimp characteristics Tensile properties librium Frictional water Number static content of crimps Crimp Initial charge (wt (peak/ eliminating Strength Elongation modulus (v.) percent) mm load (g./d.) (g./d. (percent) (g a Block polyethercapramides (BPEC):

Relative PEO content viscosity of BPEC of BPEC (wt. percent) in m-cresel Number of BPEC:

b Block polyesteramide was core, and BPEC or the mixture of BPEC and PCA;

BPEC was core and block polyesteramide was the sheath. 6 Polyeapremide (PCA). Relative viscosity in 98% sulfuric acid, 2.63.

We claim: 1. Composite fibers in which at least two polymerlc components are arranged in intimate mutual contact 6. The composite fibers of claim 5 in which the polyalkylene ether segment content of the polyether-polyamide-block-copolymer is 10 to 60% by weight, the polyalong the fiber length, and at least one of the said comalkylene ether segment content of the composite fibers 33 is 1.0 to 30% by weight, and the average recurring unit number of the alkylene oxide composing the polyalkylene ether segments is 20 to 180.

7. The composite filament of claim 6 in which the average recurring unit number of the alkylene oxide composing the polyalkylene ether segments is 25 to 140.

8. The composite fibers of claim in which the polyester component is a block-copolymer consisting of polyester segments and linear polyamide segments, the polyamide segment content of the same block-copolyrner being 0 to 30% by weight.

9. Composite fibers in which at least two polymeric components are arranged in cores-in-sheath relationship along the fiber length, and one of the said components is a fiber-forming polyester, and the other of the said components is a polyether-polyamide-block-copolymer consisting of linear polyamide segments and polyalkylene ether segments, the polyalkylene ether segment content of the block-copolymer being 3 to 85% by weight, and the polyalkylene ether segment content of the composite fibers being 0.3 to 30% by weight.

10. The composite fibers of claim 9 in which the polyalkylene ether segment content of the polyether-polyamide-block-copolymer is 8 to 60% by weight, the polyalkylene ether segment content of the composite fibers is 0.8 to 30% by weight, and the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 20 to 180.

11. The composite filament of claim 10 in which the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 25 to 140.

12. The composite fibers of claim 9 in which the polyester component is a block-copolymer consisting of polyester segments and linear polyamide segments, the polyamide segment content of the block-copolymer being 0 to 30% by weight.

13. Composite fibers in which at least two polymeric components are arranged in intimate mutual contact along the fiber length and one of the said components is a fiber-forming polyester, and the other of the said components is a mixture of a polyether-polyamide-blockcopolymer consisting of linear polyamide segments and polyalkylene ether segments, with polyamide, the polyalkylene ether segment content of the mixture being 3 to 85% by weight, and the polyalkylene ether segment content of the composite fibers being 0.3 to 30% by weight.

14. The composite fibers of claim 13 in which the polyalkylene ether segment content of the mixture of the polyether-polyamide-block-copolymer with polyamide is 8 to 60% by weight, the polyalkylene ether segment content of the composite fibers is 0.8 to 30% by weight, and the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 20 to 180.

15. The composite filament of claim 14 in which the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 25 to 140.

16. The composite filament of claim 13 in which the polyester component is a block-copolymer consisting of polyester segments and linear polyamide segments, the polyamide segment content of the block-copolymer being 0 to 30% by weight.

17. Composite fibers in which at least two polymeric components are arranged in intimate mutual contact and side-by-side relationship along the fiber length, and one of the component is a fiber-forming polyester, and the other of the said components is a mixture of a polyether polyamide-block-copolymer consisting of linear polyamide segments and polyalkylene ether segments, with polyamide, the polyalkylene ether segment content of the mixture being 8 to by weight, and the polyalkylene ether segment content of the composite fibers being 0.8 to 30% by weight.

18. The composite fibers of claim 17 in which the polyalkylene ether segment content of the mixture of polyether-polyamide-block-copolymer and polyamide is 10 to 60% by weight, the polyalkylene ether segment content of the composite fibers is 1.0 to 30% by weight, and the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 20 to 180.

19. The composite fibers of claim 18, in which the average recurring Unit number of the alkylene oxide forming the polyalkylene ether segments is 25 to 140.

20. The composite fibers of claim 17, in which the polyester component is a block-copolymer consisting of polyester segments and linear polyamide segments, the polyamide segment content of the block-copolymer being 0 to 30% by weight.

21. Composite fibers in which at least two polymeric components are arranged in one cores-in-sheath relationship along the fiber length, and one of the said component is a fiber-forming polyester, and the other of the said components is a mixture of a polyether-polyamideblock-copolymer consisting of linear polyamide segments and polyalkylene ether segments, with polyamide, the polyalkylene ether segment content of the mixture being 3 to 85 by weight, and the polyalkylene ether segment content of the composite fibers being 0.3 to 30% by weight.

22. The composite fibers of claim 21 in which the polyalkylene ether segment content of the mixture of the polyether-polyamide-block-copolymer with polyamide is 8 to 60% by weight, the polyalkylene ether segment content of the composite fibers is 0.8 to 30% by weight, and the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 20 to 180.

23. The composite fibers of claim 22 in which the average recurring unit number of the alkylene oxide forming the polyalkylene ether segments is 25 to 140.

24. The composite fibers of claim 21 in which the polyester component is a block-copolymer consisting of polyester segments and linear polyamide segments, the polyamide segment content of the block-copolymer being 0 to 30% by weight.

References Cited UNITED STATES PATENTS 3,384,681 5/1968 Kobayashi et al. 260-857 3,397,107 8/1968 Kimura 264l71 3,489,641 1/1970 Harcolinski et al. 161l73 3,493,544 2/1970 Goodman et al. 260857 ROBERT F. BURNETT, Primary Examiner L. M. CARLIN, Assistant Examiner US. Cl. X.R. 

